Bioswales work on the same principle as rain gardens. Unlike rain gardens, which are depressions, bioswales are channels, planted with the same hardy, water-tolerant species as that for rain gardens. They are more suit- able for storm-water control on a larger level. bioswales are typically found in parking lots, road medians, and parallel to roadways to better direct and filter the stormwater runoff. Organizations or communities desiring to use bioswales should spend appropriate planning time finding a location where bioswales would be most effective. The biggest advantage bioswales offer is reducing stormwater runoff. According to the American Society of Landscape Architects (ASLA), a 4-meter bioswale can reduce about 25% the of total rainfall runoff. The effectiveness of bioswales extends to their ability to filter stormwater naturally.